"To [the] best of our knowledge, this is the first demonstration of the phenomenon," study co-author Dr. Jukka Kekalainen, adjunct lecturer in the Centre for Evolutionary Biology at the University of Australia in Crawley, told The Huffington Post in an email.

The researchers have no readyexplanation for their finding, although previous research has shown that high testosterone levels can harm sperm production, the New York Daily News reported. And the finding seems to be at odds with the so-called phenotype-linked fertility hypothesis, which holds that females prefer handsome males because their offspring may enjoy hereditary benefits, such as better health and higher intelligence.

"To [the] best of our knowledge, this is the first demonstration of the phenomenon," study co-author Dr. Jukka Kekalainen, adjunct lecturer in the Centre for Evolutionary Biology at the University of Australia in Crawley, told The Huffington Post in an email.

The researchers have no readyexplanation for their finding, although previous research has shown that high testosterone levels can harm sperm production, the New York Daily News reported. And the finding seems to be at odds with the so-called phenotype-linked fertility hypothesis, which holds that females prefer handsome males because their offspring may enjoy hereditary benefits, such as better health and higher intelligence.